Indirect Estimation of Pediatric Between-Individual Biological Variation Data for 22 Common Serum Biochemistries

Abstract

These data are comparable to those reported by the Canadian Laboratory Initiative on Pediatric Reference Intervals study and the Ricos database for adults. This study reports the CVg trends and data for boys and girls by year of age, which have not been described previously.

Models to estimate biological variation components and interpretation of serial results: strengths and limitations

“…This strategy is based on the assumption that most estimates are not affected by health status because abnormal results are excluded after an outlier analysis [16]. Some examples include the studies conducted by Loh et al [17] and Loh and Metz [18] in the pediatric population assisted in primary care, with similar CV I results to those obtained in healthy adults.…”

“…The most relevant advantages of this method are that it enables assessing differences by age, gender, study duration [16][17][18] and even between different diseases [19]. As the number of subjects included in this type of studies is larger than that in the prospective studies (up to several thousand because the method is based on the laboratory database), they have a higher degree of generalizability and statistical power.…”

Paediatric reference interval and biological variation trends of thyrotropin (TSH) and free thyroxine (T4) in an Asian population

“…This step assumes that children who required only two episodes of thyroid function testing in 7 years are likely to represent patients with very mild disorder requiring only limited monitoring 4 5…”

“…As above, a scatter plot of the remaining data as a function of age was drawn and visually examined to determine appropriate age intervals for the application of outlier detection rules. Outliers were examined at three different levels: first at the level of individual laboratory result, then the level of averaged laboratory data and finally the level of total variance, as suggested by Fraser and Harris6 and performed previously 5…”

“…The combined analytical coefficient of variation for FT4 on Vitros 5600 (5.7%) and Advia Centaur (4.0%) was calculated as (5.7 2 +4.0 2 ) 0.5 =6.9%. Biological variation data were derived using the combined analytical coefficients of variation and total variation, according to the recommendations by Fraser and Harris 5 6…”